We have investigated the electrodynamic properties of high-Tc Josephson junctions (JJs) and striplines made by ion irradiation in order to evaluate the potential of such a technology for low-power rapid single flux quantum superconductor digital electronics. The process is briefly presented, together with the JJ characteristics in the context of high-speed electronics. Line inductances of d...
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Superconducting materials are known to exhibit nonlinear effects and to produce harmonic generation and intermodulation distortion in superconductive circuits. In planar structures, these nonlinearities depend on the current distribution on the strip which is mainly determined by the structure of the device. This paper investigates the current distribution at the step-in-width discontinuity in sup...
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We report on microwave frequency characterization of yttrium barium copper oxide (YBCO) thin films in both normal and superconducting states. A microwave single-post dielectric resonator technique using two different resonators was used for the complex conductivity determination of YBCO samples deposited on dielectric substrates. The intrinsic complex conductivity of YBCO films was determined from...
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For the prototype superconducting dipole magnet of the collector ring for Gesellschaft für Schwerionenforschung, Germany, the thermal radiation from outside would be shielded by the thermal shield (TS). Considering thermal and mechanical properties, the detailed structure of the TS is discussed. For example, the overview and the design concept of the TS scheme are presented. The layout of ...
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The structural evolution of premilled FeSe powder mixture was investigated by using differential thermal analysis (DTA) and X-ray diffraction (XRD) to elucidate the sintering process. The DTA results showed that the reaction process between Fe and Se powders underwent two different stages: formation of FeSe2 at the solid-solid reaction stage and formation of Fe7Se8...
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High-quality GdBa2Cu3O7-δ (GdBCO) films with thicknesses of 0.14-1.62 μm were deposited on (100)-oriented LaAlO3 substrates by photo-assisted metal-organic chemical vapor deposition technique. Evaluation of film microstructure and strain-relaxation phenomenon in the growing films and their effects on the crystallographic and superconducting...
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The electrodynamics of type-II superconductors is considered in the quasi-static limit when the concept of the so-called critical state is well applicable to the superconductors. We review analytical techniques and formulas used to describe the critical states in the superconductors of the various shapes characteristic of high-temperature superconducting materials. In particular, it is explained h...
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Alternating current (ac) losses in high-temperature superconductor tapes and devices with transport current are solved by using the resistivity-adaption algorithm (RAA). The most advanced feature of the RAA is that it enables the simulation of any model derived from the flux motion theory on finite-element analysis (FEA) packages that have an eddy current solver. The principle of the RAA, as well ...
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Usually, superconductive strands are characterized and quality controlled by performing short sample tests. These tests are often carried out using liquid cryogen or cold gas flow as coolant. However, in some measurements, the use of a more adiabatic approach is beneficial. This can be achieved with a conduction-cooled system. The advantages and the disadvantages of using a conduction-cooled measu...
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